Weapon with next round select feed system

Abstract

An improvement is made in an externally driven gun having an ammunition feeder capable of providing at least two types of ammunition to the gun by incorporating a gear transmission into the driving mechanism coupled to the ammunition feeder to appropriately control an in-feed sprocket within the ammunition feeder so that the ammunition type can be changed prior to commitment of the previously selected type of ammunition to the firing mechanism of the gun. The gear transmission which is coupled to the in-feed sprocket provides acceleration to the sprocket at the last possible moment prior to handing-off the round to the firing mechanism. In one embodiment the gear transmission includes a cam follower rotatably coupled about an offset axis to the input shaft and coupled to the output shaft through a radial slot. The cam follower is rotated by means of a stationary cam race as the follower itself is rotated as a whole by the input shaft. The output shaft is coupled to the cam follower by a pin extending into the radial slot. In a second embodiment, the gear transmission includes a planet gear rotatably coupled to the input shaft about an offset axis and engaging a stationary ring gear. A slider is provided about an offset axis on the planet gear and engages a radially defined slot in the output shaft. Both embodiments convert a substantially uniform angular velocity into an oscillating angular velocity to effect the desired acceleration of the in-feed sprocket.